JAMA Surgery: Do Bariatric Surgery Before Patients Are Morbidly Obese

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The authors find that giving patients a chance to get their BMI below 30 improves their odds of getting off medications, including insulin.

Bariatric surgery does more than help patients lose weight—it can reverse diabetes, control sleep apnea, and help patients get off medications for high blood pressure.

For these reasons, guidelines on when patients should gain access to surgery have been in flux, with the American Diabetes Association relabeling the procedures “metabolic” surgery and the American Association of Clinical Endocrinologists calling for surgery when a body mass index (BMI) is only 30 kg/m2, the minimum threshold for obesity.

Such debates, of course, also raise the question of when insurers should pay. Now comes another study in JAMA Surgery, which suggests that waiting too long misses the window when the patient can make the most meaningful progress.1

Oliver A. Varban, MD, of the University of Michigan and co-authors examined 27,320 patient records from the Michigan Bariatric Surgery Collaborative, covering a period from 2006 to 2015. They identified what factors before surgery would predict a patient’s ability to get below a BMI of 30 after surgery—in other words, no longer be obese. They also looked at which patients had complications in the month after surgery and which ones experienced remission from diabetes or hypertension.


They found that 9713 patients (36%) achieved a BMI of less than 30 a year after surgery. A major predictor was having a BMI of less than 40 before surgery (odds ratio, 12.88; 95% CI, 11.71-14.61; P <.001), and patients who had the sleeve gastrectomy, gastric bypass, or duodenal switch methods were more likely to achieve a BMI below 30 than those who had adjustable gastric banding. Only 8.5% of those who started with a BMI of 50 achieved a BMI of 30 after surgery.

A BMI of 40 is considered morbidly obese, according to the CDC.

Patients who achieved a BMI of less than 30 were also much more successful in being able to stop taking medication, including:

  • medication for hyperlipidemia (60.7% vs 43.2%; P <.001)
  • insulin for diabetes (67.7% vs 50.0%; P <.001)
  • oral medications for diabetes (78.5% vs 64.3%; P <.001)
  • medications for hypertension (54.7% vs 34.6%; P <.001)

Finally, patients who were able to bring their BMI below 30 reported higher levels of satisfaction (92.8% vs 78%) compared with those who did not. This is key, because the authors report, “Patients should be counseled appropriately with respect to weight loss expectations after bariatric surgery.”

An accompanying editorial notes that studies of bariatric surgery have found that patients at lower BMI levels can achieve improved control or remission of type 2 diabetes, but questions the fact that the study does not report overall weight loss and instead focuses on whether patients achieved a BMI of less than 30. “It’s about the weight loss,” write Bruce M. Wolfe, MD, and Elizaveta Walker, MPH.2

However, the authors argue if a goal of surgery is to reduce healthcare costs going forward, it makes sense to act when chances are good that patients can get off medications, including insulin. This should be a consideration for policymakers and health plans, the authors state. “Policies and practice patterns that delay or incentivize patients to pursue bariatric surgery only once the BMI is highly elevated can result in inferior outcomes,” they write.


1. Varban OA, Cassidy RB, Bonham A, et al. Factors associated with achieving a body mass index of less than 30 after bariatric surgery [July 26, 2017]. JAMA Surgery. 2017; doi: 10.1001/jamasurg.2017.2348.

2. Wolfe BM, Walker E. It’s all about the weight loss [July 26, 2017]. JAMA Surgery. 2017; doi: 10.1001/jamasurg.2017.2349.